The advice 'drink more water for clearer skin' doesn't survive the actual physiology. Adequate hydration is essential for body function; drinking extra water beyond adequate doesn't visibly change skin in well-hydrated people.
What hydration actually does for skin
Skin gets water from the bloodstream. The body prioritises water for organs that need it most. Surplus water excretes rather than topping up the skin specifically. Studies show no measurable skin change above the threshold of adequate hydration.
What does affect skin hydration visibly
Topical humectants (hyaluronic acid, glycerin) drawing water into the stratum corneum. Occlusives (ceramides, squalane) preventing water loss. Indoor humidity above 40% in heated rooms. None of which is fixed by drinking more water.
Drink enough to keep urine pale yellow; that's adequate. Beyond that, focus on topical hydration and ambient humidity for visible skin change.